1. Field of the Invention
The present invention pertains to a control apparatus for a distribution crane, equipped with a cable bucket.
2. Background
Whenever a cable bucket, designed for the handling of bulky materials such as sand, cement and the like, is mounted on a distribution crane without any special precaution, the following problems usually arise:
During the carrier's movement, the bucket does not move horizontally, it moves up or down.
As the carrier moves in the direction that induces the upward movement of the bucket, the translation hoist, or distribution hoist of the carrier, must first overcome the friction force, and then lift the load. This hoist should, therefore, operate so as to combine the operational characteristics of both the lifting and shutting hoists.
The above statement is based on the assumption that the lifting and shutting hoists of the bucket are mounted on the crane's boom and not directly on the distribution carrier. This last method would, indeed, cause a significant overload on the boom and should, therefore, be rejected.
This invention provides a control apparatus, which eliminates the above disadvantages.